The present invention relates to a waterproof structure for charging paddles used in inductive battery chargers.
Generally, there is an induction method for charging batteries in electric vehicles. According to this charging method, as shown in FIG. 6, a charging paddle 50 is connected to a cable 63 extending from a power supply unit. The paddle 50 is inserted to a receptacle 51 of a vehicle to charge a battery.
The charging paddle 50 is provided with a primary core 52 and a primary coil 53. The receptacle 51 is provided with a secondary core 54 and a secondary coil 55. The charging paddle 50 is inserted to a slot 56 of the receptacle 51. An alternating current supplied from the power supply unit flows through the primary coil 53 to generate an electromotive force in the secondary coil 55 by electromagnetic induction. The battery in the vehicle is charged based on this electromotive force.
The charging paddle 50 has an insert head 57 that is inserted in the slot 56 of the receptacle 51 and a grip 58, which is gripped by an operator. The insert head 57 includes the primary core 52, the primary coil 53 and a circuit board 59 having a communication device. The communication device carries out wireless communication with a communication device 60 in the receptacle 51. The communication device in the charging paddle 50 receives information about the vehicle, including the battery capacity, through this communication.
The charging paddle 50 has a housing 62 formed by welding two housing components 61. The cable 63 is introduced into the housing 62 through a lead-in hole defined in the grip 58. A waterproof grommet 64 is fitted in the lead-in hole. The grommet 64 prevents water from entering the housing 62.
However, for example, if it happens that an operator drops the charging paddle 50 and cracks the housing 62, water may penetrate the housing 62. Also, if the cable 63 is pulled very strongly, the waterproof grommet 64 fails to fully seal the lead-in hole, and water may enter the housing 62 through the lead-in hole. Therefore, the circuit board 59 may get wet.
It is an objective of the present invention to provide a waterproof structure for an inductive charging paddle, which prevents the circuit board from becoming wet, even if water enters the housing of the charging paddle.
In order to attain the above objective, the present invention provides an induction type charging paddle for engaging a receptacle to charge a battery. The charging paddle comprises a housing, a circuit board which is used for controlling the charging of the battery, and a case which is located in the housing to accommodate the circuit board. The case is sealed to prevent the circuit board from becoming wet.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, which illustrate by way of examples the principles of the invention.